The invention disclosed in this application relates to a powder hair dye composition. The invention specifically relates to a powder hair dye composition containing sodium percarbonate, which is an oxidizing agent, as an essential component, and also containing sodium carboxymethyl cellulose, which is a thickener, as an essential component.
“Hair dye composition” at least encompasses “oxidation hair dye” and “hair bleach”.
“Oxidation hair dye” is used for the purpose of dyeing hair, and it at least contains an oxidizing agent and an oxidation dye and usually also contains an alkaline agent. An oxidation dye is composed of a key intermediate or of a key intermediate and a coupler. When an oxidation hair dye is allowed to act on the hair, melanin in the hair is decomposed by the action of the oxidizing agent, and also the oxidation dye is polymerized in the hair to form an oxidized dye polymer, whereby the hair is dyed to the desired hue. In an oxidation hair dye, a direct dye is sometimes incorporated for adjusting the hue of the dyed hair.
“Hair bleach” is used for the purpose of bleaching hair, and it at least contains an oxidizing agent and usually also contains an alkaline agent. When a hair bleach is allowed to act on the hair, melanin in the hair is decomposed by the action of the oxidizing agent, and the hair is bleached to a lighter color.
“Powder hair dye composition” is a powdered formulation of a hair dye composition, and the above oxidizing agent, oxidation dye, alkaline agent, and like components are also incorporated in powder form. Powder hair dye compositions are usually one-agent type, but may also be multi-agent type such as two- or more-agent type. At the time of use, a powder hair dye composition is mixed with a liquid medium such as water to form a hair dye solution for application and then applied to the hair.
Composition used for hair dyeing is categorized into temporary hair colors, semi-permanent hair colors, and permanent hair colors.
An oxidation hair dye is one of permanent hair colors. Oxidation hair dyes have excellent hair-dyeability and fastness (color sustainability) and thus are currently most commonly used. Incidentally, a hair bleach also contains an oxidizing agent, and thus hair bleaches are structurally close to permanent hair colors.
The oxidation hair dye is usually composed of a first agent in cream or liquid form containing an oxidation dye and a second agent in cream or liquid form containing an oxidizing agent. At the time of use, the first agent and the second agent are mixed and then applied to the hair to dye the hair.
Meanwhile, as another form of oxidation hair dye, those in powder form are known. Such a hair dye incorporates an oxidation dye and an oxidizing agent in the form of powders, and is mixed with a liquid medium such as water and then applied to the hair to dye the hair.
Therefore, in this application, “at the time of use” regarding a powder hair dye composition means the state in which the powder hair dye composition has been mixed with a liquid medium such as water. Meanwhile, “at the time of storage” means the state in which the composition is in powder form.
Powder hair dye compositions are characterized in that, as described above, they are easy to use, are lightweight and thus convenient to transport or carry, and can be used in portions, for example.
The following PTL 1 discloses a powder hair dye composition incorporating a sulfate or hydrochloride of N,N-bis(β-hydroxyethyl)-p-phenylene diamine, which is an oxidation dye, and an oxidizing agent. It is stated that as the oxidizing agent, percarbonates and perborates are equally preferable (PTL 1, paragraph 0009).
The following PTL 2 discloses a powder hair dye composition incorporating a dye, an oxidizing agent, and a dispersant. It is stated that as the oxidizing agent, percarbonates and perborates are equally preferable (PTL 2, paragraph 0008).